Classroom noise monitor

How to use it

1. Open this page on the computer connected to your projector or interactive board.
2. Press Start monitor and allow the microphone when the browser asks.
3. Press Full screen so the balls fill the board.
4. Let the class work normally for a minute, then move the Noise limit until ordinary working noise keeps the balls low.
5. When the room goes over the limit, the screen turns red and says “Too loud!”. Tick Beep when too loud if you want a sound cue as well.

Your settings are remembered in this browser, so the next lesson starts where you left off.

What noise level is right for a classroom?

The US classroom acoustics standard (ANSI/ASA S12.60) asks for background noise of no more than 35 dBA in an empty classroom, so that a teacher speaking at a normal voice is clearly heard at the back. With students in the room, levels are naturally much higher:

Built-in laptop microphones vary, so treat these as starting points rather than exact readings. See the decibel chart for how these levels compare with everyday sounds.

Tips that make a noise monitor work

• Agree the limit with the class before you start. A target they helped set is easier to keep.
• Use it for a goal, not a punishment. “Keep the balls under the line for ten minutes” works better than calling out the loudest table.
• Change the limit with the activity. Group work needs a higher limit than silent reading.
• Place the laptop in the middle of the room if you can, so one loud table near the desk doesn’t decide the reading.
• Keep it short at first. A visual monitor is most effective in short, focused stretches.

More ideas in our guide to classroom noise levels.